In neurodegenerative disorders such as Alzheimer's, Parkinson's and Huntington's diseases, neurons may die by a form of programmed cell death called apoptosis. A major effort in the Cellular and Molecular Neurosciences section of the Laboratory of Neurosciences is aimed at establishing what triggers apoptosis in neurodegenerative disorders and how neuronal degeneration might be prevented by targeting specific molecular events in the process of apoptosis. We have found that a protein called p53 is involved in the death of neurons in experimental models of Alzheimer's, Parkinson's and Huntington's diseases. Novel specific inhibitors of p53 were developed and several lead agents were shown to be effective in animal models of stroke and Parkinson's disease. In other studies we established important roles for potassium ion fluxes in the pathogenesis of neuronal degeneration in models of stroke. A drug called diazoxide that opens mitochondrial potassium channels was neuronprotective in models of stroke. We have also established roles for brain-derived neurotrophic factor (BDNF) in preventing the apoptosis of neurons produced from stem cells in the hippocampus, a finding that suggests the possibility of increasing the capacity of the brain to replace lost and damaged neurons.